Field of the Invention
The present disclosure relates to a prismatic secondary battery.
Description of Related Art
Secondary batteries such as alkaline secondary batteries and nonaqueous electrolyte secondary batteries are used in power sources for driving electric vehicles (EV), hybrid electric vehicles (HEV, PHEV), and the like. In such applications, since a high capacity or a high input characteristic is required, a battery pack in which a plurality of prismatic secondary batteries are connected in series or in parallel is used.
In such prismatic secondary batteries, a battery case is formed by a bottomed tubular prismatic outer package including an opening and a sealing plate that seals the opening. The battery case accommodates therein an electrode body including positive electrode plates, negative electrode plates, and separators, and an electrolyte. A positive electrode terminal and a negative electrode terminal are installed in the sealing plate. The positive electrode terminal is electrically connected to the positive electrode plates through a positive electrode collector, and the negative electrode terminal is electrically connected to the negative electrode plates through a negative electrode collector.
The positive electrode plate includes a positive electrode core body made of metal and a positive electrode active material layers formed on the surface of the positive electrode core body. A positive electrode core body exposed portion, on which no positive electrode active material layers is formed, is formed in a portion of the positive electrode core body. Furthermore, the positive electrode collector is connected to the positive electrode core body exposed portion. Furthermore, the negative electrode plate includes a negative electrode core body made of metal and a negative electrode active material layer formed on the surface of the negative electrode core body. A negative electrode core body exposed portion, on which no negative electrode active material layer is formed, is formed in a portion of the negative electrode core body. Furthermore, the negative electrode collector is connected to the negative electrode core body exposed portion.
For example, Japanese Published Unexamined Patent Application No. 2009-032640 (Patent Document 1) proposes a prismatic secondary battery using a wounded electrode body including a wounded positive electrode core body exposed portion at one end portion and a wound negative electrode core body exposed portion at the other end portion. Furthermore, Japanese Published Unexamined Patent Application No. 2008-226625 (Patent Document 2) proposes a prismatic secondary battery that uses an electrode body provided with a positive electrode core body exposed portion and a negative electrode core body exposed portion at one end portion.